Controlling a computer display with a human pointed input device, such as a computer mouse, is an indirect process. Conventionally, the user's hand moves the mouse on a planar surface, and the response is feedback on a viewing plane, i.e. a display. It takes time to get used to the relationship between the mechanism of movement, e.g., the mouse, and the visual response on the viewing plane. Experience improves the relationship, but the accuracy is still limited as when someone tries to draw or write one's own name with a computer mouse.
In addition, display screens need to be large to show lots of data. Large screens can be costly and consume energy. Many graphic oriented programs, such as a drawing or paint program, require a user selection of work tools for drawing, modifying, selecting pen widths, selecting colors, etc. Such work tools are commonly organized on a toolbar. Such toolbars encroach on the workspace available for graphics creation on each given display screen. Thus, even larger display screens are required to see the desired level of detail.
Large displays are often difficult to use in confined working spaces (e.g. airplane drop down trays). For example, if the traveler tries to get some work done using his/her laptop computer while on a crowded aircraft, the traveler must set up the laptop computer with a cable connected to the computer mouse on the small drop down tray table on the aircraft which generally has insufficient room for both the laptop computer and its mouse. Integrated track pads are now often used, however their feedback response is inferior to that of a separate mouse. Also, with regard to confined working spaces, large displays are not private, and confidential information can be seen easily within a relatively large radius in front of the display.
Also, modern travelers often carry a brief case full of electronic equipment such as a laptop computer, a computer mouse, a removable data storage device (e.g., floppy disk drive, CD burner, etc.) with a pigtail cable to the computer, a cell phone, a personal digital assistant (PDA), etc., and a power converter and recharger for each. A cell phone might be adapted for use as a computer mouse to save on the number of devices. U.S. Patent Publication 2005/0007343 of Butzer describes a cell phone mouse that incorporates some of the computer mouse functions in a cell phone.